Dev Description: Wasp (Spider): "One of my personal favorites, Wasp is a flying version of Spider, which swaps assassinate for stun. With Wasp's already high innate damage, being able to stun (which can combine with Self-Defense for some major clear outs) can definitely be a huge bonus in certain situations. She also flies, which makes her immune to slug poison. To compensate, her health upgrades are slightly less then Spider's."
Description: Since Wasp lacks the ability to do as many critical hits than Spider does, it is recommended to have Superior Assassin or Night Hunter as an ability. Upgrading weapons also increases likelihood of critical hits, so that can help make up the problem as well. Wasp is a more general role for Spider, making her a better option for coliseum than Spider, yet not so much for adventure. But, if you see there is nobody who's immune to poison on the team, then Wasp may still be a great option because of her flight.
Recommended Level-Ups: Unless you've got someone like Beetle on the team, Stun should be upgraded first. Health is very unimportant since it gives hardly any more. Self Defense is much more useful for durability and should be after or with Speed.